It is known that a component can be separated from a gas mixture by cooling the gas mixture so that the related component is frozen out. German Preliminary Published Application 34 22 417, for example, shows such a process. This process principle is applied in industrial practice, for example, to freeze out and recover solvent vapors from exhaust gases. In an installation of this type, liquid nitrogen is used as a cooling source for cooling a circulation gas to the desired low temperature. The impurities are condensed out in two groups of reversible heat exchangers which are charged with the circulation gas. Each group consists of two precoolers and one low temperature cooler. While the impurities are condensed out in one group, they are thawed in the other group.
With this known process, solvent vapors can be effectively removed from exhaust gases but the control of the process is difficult and expensive.